Drive housing for a mowing machine

ABSTRACT

A mowing machine has a plurality of drive housings that are associated with the cutting units. Each unit has a carrying shaft that rotates a carrying unit which includes a carrying arm, cutting blades, and a covering disc. The carrying shaft is connected by gearing, located within the sealed drive housing, to the mowing machine&#39;s drive shaft. When the machine is in operation, the resulting friction within the drive housing causes the lubricants and air therein to expand. A channel is provided in the carrying shaft that opens at its lower end into the drive housing and at its upper end at the top of the carrying shaft under a conically configured cup spring, into a space which is not sealed from ambient pressures. The channel thus functions as a pressure vent to the otherwise sealed drive housing and permits the lubricants and air therein readily to expand and contract. The cup spring protects the channel from receiving any substantial amounts of dust or like contaminants in the air in the vicinity of the mowing machine.

RELATED APPLICATION

This application is a division of U.S. patent application Ser. No.772,465 filed Sept. 4, 1985 for A MOWING MACHINE of Edwin Van Der Lelyet al, U.S. Pat. No. 4,693,062, of Sept. 15, 1987.

SUMMARY OF THE INVENTION

This invention relates to a mowing machine for mowing crop, comprising acutter bar having a cutting unit which is rotatable about an upwardlyextending rotary axis.

According to the present invention an engaging member is releasablyprovided on the upper face of the cutting member. The engaging membercan be fitted to the cutting unit to assist the displacement of the cropover and across the cutting units and the cutter bar to the rear,particularly when mowing crop which tends to pass less easily over thecutting units and the cutter bar. The mowing machine can be used withoutthe engaging members when mowing crop which passes easily over thecutting units and the cutter bar to the rear during the operation of themowing machine.

An advantageous embodiment of the mowing machine in accordance with theinvention is obtained when the engaging member is fastened to asupporting member or body, which is releasably mounted on the cuttingunit.

In a further embodiment of the mowing machine in accordance with theinvention the engaging member has a V-shaped section, the ends of thelimbs being rigidly secured to the body. The resulting shape of theengaging member has an advantageous effect on the displacement of thecut crop over and across the cutting units and the cutter bar.

In another aspect of the present invention, the cutting unit is movablyarranged on a carrying shaft journalled in the cutter bar and extendingupwards therefrom. The cutting unit is slightly movable with respect tothe rotary shaft when encountering obstacles. In this way damage to thecutting unit and other components of the mowing machine is avoided.

A further advantageous embodiment is obtained when the cutting unit isresiliently mounted on the top end of the carrying shaft.

A simple construction is obtained when the cutting unit comprises acarrying arm having an angled opening which fits, with clearance, aroundan angled top end of the carrying shaft of the cutting unit, thecarrying arm being tiltable about the top end of the carrying shaft.

A mowing machine embodying the present invention can be advantageouslyconstructed by fastening the cutting unit to a carrying shaft journalledin a drive housing of the cutter bar, which cutter bar is assembled fromintermediate pieces and drive housings interconnected by a tie rod.

An advantageous support for the cutter bar of the mowing machine isobtained by providing the drive housing with a supporting skid which isrigidly secured to the rear of the drive housing, with respect to thenormal direction of operative travel of the mowing machine, the front ofthe supporting skid being coupled with the drive housing by a noseprovided on the drive housing and engaging a recess of the supportingskid. In this way the supporting skid can be readily fastened to thedriving housing. The connection at the rear of the housing is unlikelyto be damaged during operation. The supporting skid can furthermore bereadily removed for replacement, if necessary, by a different supportingskid.

In a further embodiment of the mowing machine in accordance with theinvention the cutter bar is fastened at its inner end to a gear box, towhich a support frame is connected, by means of which the mowing machinecan be coupled with the lifting device of a tractor or similar vehicle.The support frame can turn with respect to the cutter bar about apivotal axis which is substantially normal to the length of the cutterbar and the support frame is connected with the gear box by means of aforked member which can turn over and across the gear box for turning atleast part of the supporting frame over and across the gear box to aposition above the cutter bar. The mowing machine can thus be reduced inits overall dimensions, which is particularly advantageous when shippingthe mowing machine.

For a better understanding of the present invention and to show how itmay be carried into effect, reference will now be made, by way ofexample, to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a mowing machine in accordance with theinvention;

FIG. 2 is an enlarged plan view of part of the mowing machine of FIG. 1;

FIG. 3 corresponds to FIG. 2 but shows a different embodiment;

FIG. 4 is an enlarged view of part of the mowing machine taken on theline IV--IV in FIG. 1;

FIG. 5 is an enlarged view of part of the mowing machine taken on theline V--V in FIG. 1;

FIG. 6 is an enlarged plan view showing three cutting members of themowing machine;

FIG. 7 is an enlarged sectional view taken on the line VII--VII in FIG.6;

FIG. 8 is a sectional view taken on the line VIII--VIII in FIG. 6;

FIG. 9 is a view taken on the line IX--IX in FIG. 8;

FIG. 10 is an enlarged sectional view of the detail indicated in FIG. 8by the arrow X;

FIG. 11 is an enlarged sectional view of the detail indicated in FIG. 8by the arrow XI;

FIG. 12 is a sectional view taken on the line XII--XII in FIG. 6; and

FIG. 13 is a partly sectioned view of the mowing machine packed, in acollapsed condition, in a crate for transit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The mowing machine shown in the drawings comprises a support frame 1carrying a cutter bar 2. The cutter bar 2 is provided with a pluralityof cutting units 3 arranged in a row. The cutter bar is assembled fromintermediate pieces 4 and drive housings 5, which are held together by atie rod 6.

The support frame 1 comprises a mounting trestle 10 provided withcoupling pins 11 and coupling lugs 12 for hitching the frame 1 to thethree-point lifting device of a tractor or similar vehicle. The trestle10 is connected by an upwardly extending pivotal shaft 13 to a verticalframe beam 15. The vertical frame beam 15 is connected to a carrying arm16 by a pivotal shaft 17 which extends substantially in the normaldirection of operative travel of the mowing machine, as indicated by anarrow 112. The trestle 10 is also connected to the carrying arm 16 by ashear mechanism 14. At the end of the carrying arm 16 away from thepivotal shaft 17 there is a fork arm 18. On the opposite side of thecarrying arm 16 from the fork arm 18, a bracket 19 is fastened to thearm 16. A strip 20 is fastened to the end of the carrying arm 16 andextends between the bracket 19 and the fork arm 18. A fork arm 21 issecured by bolts 22 to the bracket 19. The fork arms 18 and 21 aresituated on opposite sides of a bearing housing 23, which is connectedwith a gear box 24. The cutter bar 2 is fastened to the lower end of thegear box 24.

The fork arms 18 and 21 can turn about the center line 28 of a driveshaft 25 which is journalled in the bearing housing 23. The bearinghousing 23 contains meshing bevel gear wheels 26 which drive two meshingspur gear wheels 27 in the gear box 24. The drive shaft 25 carries apulley 31 which is connected by three belts 38 to a pulley 32. Thepulley 32 is mounted on a shaft 33 which is journalled in a supportinglug 34 fastened to the carrying arm 16. The pulley 31 and the belts 38are surrounded by a protective casing 35.

A tension spring 36 acts between the top of the frame beam 15 and thecarrying arm 16. A stop 37 fixed to the carrying arm 16 limits themovement of the carrying arm 16 about the pivotal shaft 17 with respectto the beam 15.

An angled support 41 is secured to the top of the bearing housing 23 andthe gear box 24 and comprises a top plate 42 and a side plate 43. Asupport 44 is fastened to the top plate 42 and is provided with acarrier 45 for a fabric screen 49. The carrier 45 extends parallel toand above the cutter bar 2. The carrier 45 is provided with supports 46to which rails 47 and 48 are fastened, over which the fabric screen 49is arranged. The end of the carrier 45 away from the supporting frame 1is provided with a protective bar 50 having a fastening rod 51 which isreleasably fastened in the hollow end of the carrier 45. The top plate42 and the support 44 are provided with a substantially horizontal pin55, about which a coupling segment 56 is rotatable. A lifting cylinder57 acts between the coupling segment 56 and the top of the frame beam15.

The mowing machine shown in FIG. 2 comprises four cutting units 3. Thecutter bar 2 comprises four identical intermediate pieces 4 and fouridentical drive housings 5. The intermediate pieces 4 and the drivehousings 5 are held together by the tie rod 6 and are fastened to thelower end of the gear box 24. The tie rod 6 is solid (i.e. continuous)and has a circular section with a diameter 61 (FIG. 5) of thirtymilimeters. FIG. 3 shows an embodiment having five cutting units 3. Anintegral continuous drive shaft 62 extends through the intermediatepieces 4 and the drive housing 5. The drive shaft 62 has an angularcross-section which, in the illustrated embodiment, is square. The driveshaft 62 is journalled at one end in the underside of the gear box 24,where it is in mesh, via a small spur gear with the lower gear wheel 27as shown in FIG. 5.

Each drive housing 5 carries a cutting unit 3. The cutting units 3 arerotatable about upwardly extending rotary axes 63, which are vertical inthe horizontal working position of the mowing machine. The rotary axes63 of all of the cutting units lie in the same plane which contains thecenterline of the drive shaft 62. The construction of the drive housings5 is shown in detail in FIGS. 7 to 10 for the drive housing located atthe outermost end of the cutter bar 2. These figures and FIGS. 6 and 12also show in detail the construction of the cutting units.

Each cutting unit 3 comprises a carrying arm 66, which extends for equaldistances to both sides of the rotary axis 63. The carrying arm 66 hasan angular (shown square) opening 67 which receives, with someclearance, a correspondingly shaped top end 68 of a carrying shaft 69journalled in the drive housing 5. On top of the carrying arm 66 thereis a disc 71, which is circular, as viewed on plan, with its center linecoincident with the rotary axis 63. Blade carriers 72 are provided onthe undersides of the ends of the carrying arm 66. The blade carriers 72and the disc 71 are fastened to the carrier 66 by flat-headed bolts 73and machine bolts 74, the centerlines of which lie in a vertical planecontaining the rotary axis 63. The machine bolts 74 are nearer therotary axis 63 than the flat-headed bolts 73. The blade carriers 72 haveprojections 75 (FIG. 9) on their lower faces, about which cutting blades76 are rotatable. The projections 75 define recesses 77 which receivelugs 78 on the bolts 73, so that the bolts 73, when inserted, cannotturn. Each blade carrier 72 has a stop 79. The bolts 73 are secured inplace by nuts 80. The disc 71 has a raised ridge 81 which extends aroundthe bolt 73 and its nut 80 to the periphery of the disc 71. The machinebolt 74 is on the opposite side of the ridge 81 from the nut 80. Eachcutting unit 3 is provided with two cutting blades 76, which arediametrically opposite each other with respect to the axis 63. At theperiphery of the disc 71 and midway between the two cutting blades 76 oneach cutting unit 3, the disc 71 has upwardly bulging parts 82, which,in the illustrated embodiment, are offset about the axis 63 through 90°with respect to the blades 76.

The shaft 69 has at its lower end a bevel gear wheel 85 whichco-operates with a bevel gear wheel 86 rotationally fixed to the driveshaft 62. The bevel gear wheel 86 is part of a sleeve 87 journalled inbearings 88 and 89 in the wall 70 of the drive housing 5. The spacebetween the sleeve 87 and the inner side of the wall 70 is sealed fromthe outside by closing elements 90 provided on the outer side of thebearings 88 and 89. The bearing 89 bears in the axial direction on aring 91, which lies in a groove 92 in the wall 70. One or more spacerrings 93 can be provided, if necessary between the bearing 89 and thering 91 to ensure correct location of the bearing 89 in the housing andsatisfactory meshing of the teeth of the bevel gear wheels 85 and 86.Near the bearing 88 a further ring 91 lies in a groove 92 in the wall 70to locate the sleeve 87 in the housing 70. The bores in the wall 70adjoining the adjacent intermediate pieces 4 or a closing plate 94 areprovided with alignment rings 95. Near the gear wheel 86 the sleeve 87has a hole 96 which corresponds to the section of the shaft 62 and inwhich the shaft 62 fits. The remaining length of the sleeve 87 maysurround the shaft 62 with ample clearance and its sectional shape neednot correspond to the section of the shaft 62.

The carrying shaft 69 is journalled in bearings 100 supported in a cover97 of the drive housing 5, which cover lies over an upper opening 98 inthe wall 70 and is rigidly secured by bolts 99 to the wall 70. Thebearings 100 in the cover 97 are covered at the top by a closing ring101. The closing ring 101 is provided with one or more spacer rings 102,on which a closing hood 103 is arranged. The closing hood is rotatableby an opening (not shown) with the carrying shaft 69 about the top end68 of the carrying shaft. The carrying arm 66 lies on the closing hood103. The carrying shaft 69 has a screwthreaded end 104 which receives anut 105. Between the nut 105 and the top of the carrying arm 66 there isa resilient ring member comprising a cup spring 106 which urges thecarrying arm 66, the hood 103 and the rings 101 and 102 firmly againstthe parts of the upper bearing 100 which rotate with the shaft 69. Thenut 105 and the cup spring are situated below the central part of thedisc 71 covering the whole length of the carrying arm 66.

The carrying shaft 69 has a channel 107 opening at one end near therotary axis 63 in the interior of the drive housing 5. The other end ofthe channel 107 opens at the top end of the carrying shaft to below thecup spring 106 at a position away from the axis 63.

Below each carrying shaft 69, beneath the cutter bar, there is asupporting skid 110. The skids 110 are situated mainly below the drivehousings 5 and are secured to them. The rear edge of each skid 110 has awidth 130, which is substantially equal to the width of the drivehousing 5. The width of the skid widens to the front to become equal tothe width 131 near the front of the cutter bar 2. At the rear of thecutter bar 2, viewed with respect to the direction 112, the supportingskids are provided with upwardly directed parts 113, which are fastenedby bolts 114 to the housing 5. The supporting skids are provided withsegment-shaped protective members 115 disposed in front of the cutterbar with respect to the direction 112. The outer periphery 116 of eachmember 115 is centered on the rotary axis 63 of the cutting memberconcerned. The outer periphery 116 of each protective member 115 issituated approximately directly below the circumferential edge of thedisc 71 and extends radially beyond the bolt 73 which connects the bladeto the carrier arm 66. At the top, the protective member 115 has a plate117 which is parallel to the plane in which the cutting blades 76 move.The rear edge 118 of the plate 117 adjoins the drive housing 5 andextends at the side of the drive housing 5 to positions near the frontof each intermediate piece 4. Between the top plate 117 and a bottomplate 119 of the skid 110, there are two spaced support plates 120 whichextend, as viewed on plan, parallel to the lengthwise direction of thecutter bar 2 (FIG. 6). A gap 121 is left between the supporting plates120, in which fits a nose 122 on the front of the drive housing 5. Theheight of the nose 122 is such that its lower edge 123 contracts the topof the bottom plate 119 of the supporting skid 110, and its top edge 124contacts the underside of the top plate 117.

The underside of the supporting skid 110 is provided with a sliding shoe125, the rear end of which is fastened by the bolts 114 to the rear ofthe housing 5. The front edge of the sliding shoe 125 has an upwardlydeflected lug 126 which fits into a hole 127 in the bottom plate 119 ofthe protective member 115. The sliding shoe 125 is narrower than thesupporting skid 110 and has a width 128, which is slightly smaller thanthe width of the drive housing 5. At the front, the supporting skid 110has a width 131 equal to about twice the width 129 of the housing 5.

The cutting unit 3 farthest from the support frame 1 is provided with anupwardly extending body 135 in the form of a drum. The body 135 has acontinuous bottom plate 138, which has the same shape at the top of thedisc 71. The disc 71 has a central, upwardly extending, conical part 136having an annular depression 137. The bottom plate 138 of the body 136fits over the central part 136 and is centered and lightly securedthereon by an annular depression 139 which engages the depression 137.At its periphery, the bottom plate 138 is provided with protruding lugs140. An upwardly tapering conical jacket 141 is supported on the bottomplate 138 and has a top plate 142 extending at right angles to therotary axis 63. The jacket 141 tapers at an angle 143 of about 10° tothe rotary axis 63. The lower edge of the jacket 141 has two protrudinglugs 144 which have the same size as and match the top faces of the lugs140. The lugs 140 and 144 have openings which are in register with holesin the disc 71 and through which the machine bolts 74 pass to secure thesupporting member 135 with the disc 71 to the carrying arm 66. Theconical jacket 141 is provided with two engaging members 145 having anangled, V-shaped section comprising two limbs, the outer ends of thelimbs being welded or otherwise appropriately fastened to the jacket 141or fastened to it in a different. The two engaging members 145 arediametrically opposite each other with respect to the rotary axis 63.The height 146 of the body 135 is not critical; in the illustratedembodiment it is approximately equal to the distance between theunderside of the skid 110 and the top side of the carrying shaft 69,i.e. about fifteen centimeters.

The cutting units 3 other than the outermost cutting unit of the row maybe provided with bodies 150 provided with engaging members 153. One suchbody is shown in FIG. 6, on the penultimate cutting unit 3 of the rowand in FIG. 12 in a sectional view. The body 150 mainly comprises aconical plate having an annular depression 151 which engages thedepression 137 of the disc 71. The body 150 has substantially the sameshape as the conical, central parts 136 of the discs 71 and has lugs 152by means of which the body 150 is secured with the disc 71, to thecarrying arm 66 by the bolts 74. The body 150 is substantially identicalto the bottom plate 138 of the body 135. The body 150 is provided withdiametrically oppositely disposed engaging members 153 which, like theengaging members 145 of the body 135, have angled, V-shaped sections,the ends of the limbs being fastened to the upper surface of the body150.

The drive housing 5 at the outermost end of the cutter bar 2 is providedwith a swath guide 155. The swath guide 155 is fastened by means of aplate 156 to the rear of the housing 5 using the bolts 114 which alsosecure the supporting skid 110 to the housing 5. The swath guide 155comprises a cranked supporting plate 160, which is fastened to theclosing plate 94. The plate 160 has a fastening element 162, to which isfastened a guide plate 161 provided with a guide bar 163. The guide bar163 is inclined inwardly of the direction 112 at an angle 158. The end164 of the guide bar 163 lies in a vertical plane 159 extending in thedirection 112 and going at least substantially through the side of thepenultimate cutting unit facing the support frame 1. The end 164 lies ata distance 157 of about 115 centimeters behind the cutter bar 2. Theguide bar 163 slopes slightly upwardly away from the guide plate 161.

Near the junction of the cutter bar 2 with the gear box 24 there is asupporting inner skid 165 which is disposed below the gear-box 24 andthe adjacent intermediate piece 4. This inner skid is fastened by bolts166 to a lug 167 secured to the rear of the gearbox 24. In front of thegearbox 24, the skid 165 has a lug 168, which is rigidly secured by abolt 169 to the gearbox 24. The inner skid 165 has a curved part 170which extends approximately up to the height of the drive shaft 25. Thetop end of the curved part 170 is connected by means of a strip 171 tothe gearbox 24. Like the supporting skid 110, the inner skid 165 isprovided with a sliding shoe 172, the rear edge of which is fastened bybolts 188 to the rear of the skid. The front of the sliding shoe 172,there is a lug 173 corresponding with the lugs 126 and engaging a hole(not shown) in the inner skid 165 corresponding with the holes 127.

A screening plate 174 is provided along one side of the inner skid 165.The screening plate 174 has a lower edge adjoining the curved part 170of the inner skid 165. The top edge 175 of the plate 174 extends betweenthe top end of the part 170 and the gearbox 24, where the top edge 175adjoins the gearbox slightly above the centerline 28 of the shaft 25.The top edge 175 has a horizontal part 176 with a lug 177, which isfastened, with the strip 171, to the gearbox 24 by a bolt 178. Thescreening plate 174 is substantially at right angles to the lengthwisedirection of the cutter bar 2.

For operation, the mowing machine is coupled by the pins 11 and the lugs12 of the fastening trestle 10 to the lifting device of a tractor orsimilar vehicle. The shaft 33 is connected by an auxiliary shaft withthe power take-off shaft of the tractor.

During operation the mowing machine is moved in the direction 112, thecutter bar 2 extending transversely of this direction. The cutting units3 cut crop in a strip lying at the side of the tractor to which themowing machine is hitched, as viewed in the direction 112. The cuttingunits are rotated in the directions indicated by the arrows 179 and 180in FIG. 2. The cutting units are driven from the shaft 33 via thepulleys 32 and 31, the gear wheels 26 and 27 and the drive shaft 62. Thedrive shaft 62 extends from the gearbox 24 through the intermediatepieces 4 and the drive housings 5. The drive shaft 62 is connected todrive the gear wheels 86 in the drive housings 5 by means of thepolygonal section of the drive shaft and the corresponding polygonalopenings 96 in the sleeves 87. From the gear wheels 86, via the gearwheels 85, the rotary shafts 69, on which the cutting units are fastenedby means of the carriers 66, are rotated. The cutting units are drivenso that the innermost cutting unit, i.e. the one nearest the supportframe 1, rotates about its rotary axis 63 in a direction 179, in whichat the front, the cutting member moves away from the support frame 1.Where there is an even number of cutting units, for example four cuttingunits as shown in FIG. 2, the other cutting units are driven so thatadjacent cutting units rotate in opposite senses to each other. Thecutting units thus form pairs rotating in opposite senses in thedirections of the arrows 179 and 180. The regions of closest approach ofthe cutting units of each pair will move to the rear with respect to thedirection 112. When the cutter bar has an odd number of cutting units,for example five as shown in FIG. 3, the direction of rotation of thecutting units is selected so that the two cutting members nearest thesupport frame 1 rotate in the same direction 179 as each other abouttheir rotary axes. In order to prevent the cutting blades of these twocutting units from contacting in an undesirable manner, they are spacedapart by an intermediate piece 183, disposed between the two drivinghousings 5 of the cutting units concerned, which is longer than theother intermediate pieces 4. The other adjacent pairs of cutting unitsrotate in opposite senses during operation of the mowing machine. Bycausing the first and the second cutting units of the row to rotate inthe same direction when there is an odd number of cutting units, thesecond cutting unit and the remaining cutting unit can co-operate inpairs moving in opposite senses so that the outermost cutting unitrotates in the desired manner in the direction of the arrow 180. Thisdirection of rotation 180 is desired in order to enable crop to bedeposited in a swath on the cutter bar by the rotation of the outermostcutting unit. The edge of the swath, as viewed in the direction 112, issome distance from the end of the cutter bar so that a strip of groundis left free of crop at the side of the swath. The direction of rotation179 of the innermost cutting unit is desired to ensure that, near theinner end of the cutter bar, the crop can move over and across itwithout accumulating in front of the gearbox 24 and the inner skid 165.

The screening plate 174 is provided on the inner skid 165 in order toprevent cut crop from moving towards the carrying frame 1 over the topof the inner skid 165 when cutting high crop. As shown in the Figures,the screening plate 174 is preferably disposed on the side of the innerskid 165 facing the row of cutting units. The length of the mowingmachine can be selected simply by assembling the cutter bar from therequired number of intermediate pieces 4 and drive housings 5. By usinga larger or smaller number of identical drive housings carrying thecutting units and a larger or smaller number of intermediate pieces, thelength of the cutter bar and the number of cutting units can readily bealtered with uniform components. If the number of cutting units isincreased, the pulleys may need to have more grooves, as shown in FIG.3, in order to transfer the driving force from the shaft 33 to the shaft25. The section of the drive shaft 62 is selected that it issufficiently strong to drive more or fewer cutting units. By arrangingthe outermost cutting member of the row so that it protrudes beyond itsdrive housing 5, constituting the end of the cutter bar, it is ensuredthat uncut crop on the strip of soil adjacent the strip being mowed bythe mowing machine will not touch the cutter bar, or be otherwiseaffected by it. The cutter bar is then as short and as inexpensive aspossible. During rotation of the cutting units, the blades 76 cut thecrop, and the crop then passes over the top of the cutting units to therear during travel of the mowing machine in the direction 112. Thismovement is assisted by the rotation of the cutting units, since inparticular the rearwardly moving parts of the cutting units push themown crop to the rear. When the long crop is being mown, it passes overand across the cutting units to the rear substantially throughout thelength of the cutter bar. The swath guide 155 at the end of the cutterbar guides the crop slightly inwardly i.e. towards the junction betweenthe cutter bar and the support frame 1. Thus at the side of the formedswath is left a strip of ground free of mown crop. The position of theend of the swath guide is such that the strip of ground has the desiredwidth. In particular the body 135 arranged on the outermost cuttingunit, with its engaging members 145 will assist in keeping the strip ofground free of mown crop. This body 135 will displace the crop cut bythe outermost cutting unit in the direction of the arrow 180 to pass itto the rear of the cutter bar 2. The engaging members 145 contribute inpassing the crop from the cutting unit 135 in the direction of the arrow180 to the rear of the cutting bar. The engaging members areparticularly useful when cutting heavy humid crop, since otherwise thesmooth periphery of the drum jacket 141 would be likely to slide alongthe crop. The height 146 of the body 135 may be larger or smaller thanillustrated, for example to suit the kind of crop to be mown by themowing machine. The depressed rims 139 of the bottom plates 138 ensuresatisfactory location of the body 135 on the top of the discs 71.

When the more or less smooth top of the discs 71 of the cutting unitscannot grip the crop adequately to assist the movement of the crop overand across the cutter bar, for example when cutting heavy, wet crop, theengaging members 153 can be provided on the top of the cutting units.For this purpose, as is shown in FIGS. 6 and 12, bodies 150 providedwith engaging members 153 are fitted to the discs. Depending on the cropto be mown, these bodies 150 can be fitted to or removed from thecutting units. Fitting and removing of the members 150 can be carriedout simply by means of the connection via the bolts 74 on the carrier 66and the discs 71. Satisfactory centering of the bodies 150 on the discs71 is ensured by the depressions 151, which fit in the depressions 137of the discs 71.

The carrying arm 66 with the parts mounted on it is slightly movablewith respect to the carrying shaft 69 so that the carrier 66 can tiltrelatively to the top end 68 of the carrying shaft 69. The carrying arm66 is prevented from turning about the rotary shaft 69 by means of thecooperating shapes of the opening 67 and the top end 68 of the carryingshaft 69. The tilting movement of the carrying arm 66 with respect tothe carrying shaft 69 occurs when the cutting unit comes into contactwith large obstacles such as stones. The cutting unit, formed by thecarrying arm 66 and the parts fastened to it, can then slightly deflectby tilting. The energy required to undergo this tilting deflectionneutralizes wholly or partly the energy produced by impact of thecutting unit on the obstacle so that damage to the cutting unit isavoided. It is an advantage that the cutting unit can deflectresiliently. For this purpose the cup spring 106 is provided between thecarrying arm 66 and the nut 105. This cup spring 106 has a maximumdeflection of four millimeters. In the assembled state the cup spring iscompressed by about one and a half millimeters. The cup spring tends tohold the carrying arm and hence the cutting unit 3 in the desiredposition relative to the carrying shaft 69. At maximum compression thecup spring 196 exerts a counter-pressure of about 1500 kilograms. Theshape and rigidity of the disc 71 itself is such that it can distortupon impact with large obstacles without damage to the carrying arm 66with the blades and/or other parts of the machine. Any damaged disc 71can easily be replaced by a new one on the carrying arm. By fasteningthe bodies 150 and 135 to the disc 71 its rigidity is increased. Whenthe bodies 150 and 135 are provided on the disc 71 it is particularlyimportant for the cutting units to be resiliently tiltable on thecarrying shaft 69 in order to avoid damage in the event of contactbetween the cutting units and an obstacle. In the event of seriousdamage, the cutting blades 76 might fly loose of the cutting unit, butthey are then captured by the screening fabric 49. The screening fabric49 will also capture stones or other loose material ejected by therotation of the cutting units so that this material cannot fly out anddamage objects at some distance. The blades 76 themselves are capable ofdeflection and turn underneath the disc 71. Such turning is limited bythe stops 79 in order to prevent the blades 76 from coming into contactwith parts of the cutter bar.

At the front of the cutter bar 2, the undersides of the cutting unitsare protected by the sectorshaped parts 115 of the supporting skids 110.Movement of these sector-shaped parts of the skids in a direction normalto the direction 112 is avoided since the nose 122 fits into the gap 122between the supporting strips 120 and between the top plate 117 and thebottom plate 119. The supporting skids 110 can be fitted easily byslipping the skids 110 onto the nose 122 and fastening the ends 113 tothe wall 70 by the bolts 114. The bolts 114 are at the rear of thecutter bar so that damage to them during travel of the machine in normaloperation is practically excluded. In this way the connection of thesupporting skids 110 with the cutter bar 2 is satisfactorily protected.The nose 122 and the bolts 114 enable the supporting skids to be readilymounted and permit equally simple removal for repair or replacement.

The sliding shoes 125 prevent undesirably rapid wear of the supportingskids 110. The sliding shoes 125 can be readily replaced when they havebecome excessively thin. The sliding shoes 125 can easily be fitted onor removed from the underside of the supporting skids by means of thelug 126 fitting in the hole 127 and the bolts 114 which secure the rearof the shoe to the rear of the cutter bar. Again, it is advantageousthat the bolts 114 are positioned where they are unlikely to be damaged,while replacement of the sliding shoe 125 can be readily carried out.

The movement of the blades 76 about the projections 75 provided on theblade carrier 72 avoids wear of the bolt 73. The bolt 73 is preventedfrom turning by engagement of the lugs 78 in the recesses 77 between theprojections 75 so that release of the bolts 73 is avoided and screwingof the nut 80 onto the bolt 73 is also facilitated. Since the stop 79and the blade carrier 72 are formed integrally, the stop 79 is correctlypositioned relative to the blade 76 to prevent the blade 76 from turningtoo far in its movement underneath the disc 71. The blade 76 is thusprevented from striking parts of the cutter bar 2. By making the heightof the projections 75 slightly larger than the thickness of the blades76, free rotation of the blades is ensured. Jamming of the bladesbetween the blade carriers and the head of the bolt 73 is thus avoided,while mounting of the blades is facilitated.

The axial forces exerted by the gear wheel 86 on the bearings 89 whenthe cutting units are driven, can be satisfactorily transferred throughthe spacer rings 93 to the ring 91 utilize as desired. Since it ispossible to thicker or thinner spacer rings 93, correct location of thegear wheel 80 with respect to the gear wheel 85 is facilitated. When thecutting unit and the carrying shaft 69 with the gear wheel 85 fastenedon it are driven in a sense opposite that of the gear wheel 85 of FIG.8, the sleeve 87 is fitted so that the gear wheel 85 will be nearer thebearings 88. The spacer rings 93 are then provided at the bearing 88 inorder to transfer the axial forces exerted by the gear wheel 86 to therespective supporting ring 91. The inclination of the channel 107 in theshaft 69 results in a sufficiently light centrifugal force on any partsof this channel to ensure that the channel 107 is unlikely to becomeclogged, so keeping the space in the wall 70 in communication with theopen air. Consequently the lubricants and air in the interior of thehousing 5 can readily expand and contract. The alignment rings 95bridging adjoining edges of the intermediate pieces 4 and the drivehousings 5 or of the closing piece 94 and the outermost housing 5improve the rigidity of the cutter bar 2. The parts 4 and 5 which mainlyconstitute the cutter bar 2 are pressed towards one another by thetension in the tie rod 6. This stress can be adjusted by means of thenut 182 at the end of the tie rod, the end of the tie rod 6 in thegearbox 24 being axially fixed.

In order to protect vital parts of the machine against obstacles, theprotective bar so is mounted on the outer side of the screening fabric149. The bar 50 protects persons standing too near to the end of thecutter bar against contact with the cutting units

For the purposes of shipping the machine, the carrying frame 1 isdesigned so that it can be turned through about 180° with respect to thecutter bar 2 about the centerline of the shaft 25. To this end, forkedarms 18 and 21 are spaced apart by a distance exceeding the width of thegearbox 24 and the housing 23. The forked arms 18 and 21 havefurthermore such a length that the housing 23 is a distance 187 from thestrip 20 and the arm 16 can be turned over the top of the gearbox 24.The carrying arm 16 with the frame beam 15 fastened to it can be movedinto the position shown in FIG. 13. To effect this turn of the carryingarm 16 with respect to the cutter bar 2, the fastening trestle 10 isdisengaged from the bar 2. Moreover, the shear mechanism is removed fromthe trestle 10. In order to put the mowing machine in the crate 186, theprotective bar 50 is removed from the screening fabric carrier 45. Thefabric screen 49 is removed from the rails 48 and 47 and the rails 47and 48 are removed from the carrier 45. The carrier 45 is removed fromthe gear wheel box by releasing the top plate 42 and the side plate 43.The cylinder 57 with the segment 56 is detached from the pin 55.Otherwise all parts can remain on the mowing machine, and the remainingparts fastened to the carrying frame 1 can remain in place. Thetransmission gear formed by the pulleys 31 and 32 and the protectingcasing 35 can also remain fastened to the carrying frame 1. Also thespring 36 can remain fastened to the carrying beam 16 and the frame beam15.

When the cutter bar 2 and the cutting members 3 fastened thereto are putin the crate 186, the carrying beam 16 being tilted over, the rails 47and 48 can be disposed along an upright side of the crate. The fabricscreen 49 can be put along a short side of the crate. The trestle 10 canbe put at one end of the tilted-over carrying beam 16 with the framebeam 15 as shown in FIG. 13. The inner skid 165 can be disconnected fromthe gear box 24 and be arranged in the crate 186. Thus the crate 186need not have a length much greater than the length 189 corresponding tothe length of the cutter bar 2 and the gear boxes 23 and 24 fastened toit. The width of the crate need not be much larger than than thediameter 194 of the cutting members. The height 191 of the crate 186 isabout twice the height of the gear box 24. In this way the mowingmachine can be packed in a relatively small space, which facilitatesshipping.

Although various features of the mowing machine have been described, andare illustrated in the drawings will be set forth in the followingclaims as inventive features, the invention is not necessarily limitedto these features and may encompass all inventive features disclosedbeen described both individually and in various combinations.

Having disclosed our invention, what we claim as new and to be securedby Letters Patent of the United States is:
 1. A drive housing for amowing machine comprising; a sealed outer wall which contains an inputdrive shaft, an output carrying shaft, and means for transferring thepower from said drive shaft to said carrying shaft wherein the drivehousing accomodates a sleeve which is coupled with said drive shaft andhas a bevel gear wheel, said sleeve bearing axially, under forcesimposed by the bevel wheel gear when a cutting unit is driven, on asupporting ring through as least one spacer ring, said supporting ringbeing rigidly secured in the drive housing.
 2. A drive housing for amowing machine as claimed in claim 1, wherein said carrying shaft onwhich said cutting unit is mounted has a channel communicating between aspace in said drive housing and ambient surroundings, a lower end ofsaid channel opening into said space in said drive housing and anopposite, upper end opening into a further space located below a discthat provides an upper covering for said cutting unit, said furtherspace not hermetically sealed from said ambient surroundings.
 3. A drivehousing for a mowing machine as claimed in claim 2 wherein said channelin said carrying shaft is disposed at an angle to said carrying shaft'saxis of rotation.
 4. A drive housing for a mowing machine as claimed inclaim 2 wherein said lower end of said channel in said carrying shaft iscloser to said axis of rotation than is said opposite, upper end.
 5. Adrive housing for a mowing machine as claimed in claim 2 comprising acup ring which defines part of said further space and covers the openingto said channel therein.
 6. A drive housing for a mowing machinecomprising an outer wall which is configured to receive and contain aninput drive shaft, an output drive shaft for operating a cutting unit ofthe mowing machine, means for transferring power from said input driveshaft to said output drive shaft, said output drive shaft extendsupwardly from the drive housing and receiving at its upper aspect a ringmember, pressure venting channel means extending through said outputdrive shaft from the interior of the housing into a space under saidring member which is not sealed with respect to the ambient pressureoutside the housing, said pressure venting channel providing the onlypassage for the intake and output of air between the interior of thehousing and air at ambient pressure outside the housing, said ringmember protecting said pressure venting channel means from dust orsimilar particulate matter.